Well known in the art of trailer hitches is the two piece trailer hitch With the two piece trailer hitch, a vehicle member is mounted on the vehicle and does not protrude beyond the bumper of the vehicle. In order to make this trailer hitch effective, a removable member is slidably mounted within the first vehicle member and held therein by a pin. In this manner, a vehicle can have trailer towing capability added or removed as desired. This factor protects the trailer hitch from undesired weather wear.
This trailer hitch removability factor also improves the aesthetic appearance of a vehicle. While a trailer hitch is utilitarian, the presence of the hitch without a trailer detracts from the aesthetic appearance of a vehicle. The two-piece trailer hitch thus provides both a utilitarian and aesthetic function.
While this structure provides for a convenient method and apparatus for providing the joinder of the two-piece trailer hitch or the separation of the two-piece trailer hitch, many problems are presented. It becomes very easy to duplicate the vehicle member of that two piece trailer hitch and provide for a simple method of stealing the trailer and the item thereon by simply removing the cotterpin and separating the removable member of the trailer hitch from the vehicle member In this fashion, the removable member of trailer hitch can be easily mounted in a similar device of the vehicle member mounted on a thief's vehicle. Then the trailer is towed away together with whatever is on the trailer.
This problem is well recognized in the art, because a number of locking devices have been provided to avoid this problem. However, these locking devices have a tendency to be cumbersome and bulky, and not easily operated. It is highly desirable to provide a simple locking mechanism which is easily operable while at the same time strong enough to provide protection.
A threaded locking device is useful for solving some of the protection problems, but not strong enough to provide all of the desired protection. These devices can also be bulky and cumbersome. Additionally, the pressure of towing can release the threaded locking device. If the strength and simplicity of the threaded locking device can be achieved, while avoiding an undesired release of the locking device when in use, great advantages are obtained in trailer security.